<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		
		<style>
			
			div{
				height: 100px;
				width: 100px;
				
			}
			
			.abc{
				
				position: relative;
				background-color: green;
				
				z-index: 2;
			}
			
			#cba{
				
				background-color: red;
				
				position: absolute;
				
				top: 20px;
				
				left: 20px;
				z-index: 1;
			}
		</style>
	</head>
	<body>
		
		
		<div class="abc"></div>
		<div id="cba"></div>
		<div class="abc"></div>
	</body>
</html>
